User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20040913 Firefox/0.10.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20040913 Firefox/0.10.1 When viewing an XUL page with multiple splitters, resizing panes on an inner level before those on an outer level causes the splitters to jump. This is difficult to explain so an example is forthcoming. Reproducible: Always Steps to Reproduce: 1. Load a page with more than one level of splitters that go in the same direction. 2. Drag an inner splitter. Actual Results: Both the inner and outer splitters jump. Expected Results: The inner splitter should follow the mouse drag, and the outer one should stay put. Using Plastikfox Crystal SVG theme.
Created attachment 161539 [details] Testcase Aforementioned testcase. Also: Bug still present with default theme.
Splitters work by changing the width attributes on your boxes. This assumes that the overall preferred size is not affected by the individual preferred sizes of the split boxes. For instance, for the outermost boxes the overall preferred size is simply the window's inner width. However your left box doesn't have a preferred size so that you change the split the new width attributes will also give the left box a preferred size giving rise to the effect you describe. The easy way to work around the problem is to specify a preferred size on the parent box of the splitter (in your case width="1" works). You don't see the problem after you move the outer splitter because it gives the vbox a preferred width.